Sherrie buys a laptop computer for $600. Each year, the value of her laptop decreases by $40. How many years will it take before the laptop is not worth anything? Explain how you know your answer is correct.

Determine the fraction of total interest owed. after the fourth month of a 12-month loan: the numerator is: {(n + ) + (n + ) + (n + ) + (n + )} = , and the denominator is: {(n) + (n + 1) + + (n + )} = . therefore, the fraction is numerator/denominator (to the nearest tenth) =

Offering 30 if a plus b plus c equals 68 and ab plus bc plus ca equals 1121, where a, b, and c are all prime numbers, find the value of abc. the answer is 1978 but i need an explanation on how to get that.

Use the elimination method to solve the systems of equations.choose the correct ordered pair. 7x+4y=39